(a) Field of the Invention
The present invention relates to a thin film transistor array panel and a liquid crystal display including the panel.
(b) Description of Related Art
A liquid crystal display (“LCD”) is one of the most prevalent flat panel displays, which includes two panels having field-generating electrodes and a liquid crystal layer interposed therebetween and controls the transmittance of light passing through the liquid crystal layer by adjusting voltages applied to the electrodes to re-arrange liquid crystal molecules in the liquid crystal layer.
The most popular one among those LCDs is one having electrodes on the respective panels and having a plurality of thin film transistors (“TFTs”) for switching the voltages applied to the electrodes. Generally, the TFTs are provided on one of the two panels.
On one panel of an LCD, signal wire including gate lines for transmitting gate signals and data lines for transmitting data signals, pixel electrodes to which data signals applied via the data lines are transmitted, TFTs for controlling the data signals to be transmitted to the pixel electrodes using the gate signals, etc. are formed, and, on the other panel of the LCD, color filters for displaying color image and a black matrix for blocking leakage light between pixels and for preventing contrast ratio from decreasing are formed.
For semiconductor layers of the TFTs, hydrogenated amorphous silicon is usually used. The amorphous silicon layers are sometimes remained under the wire to prevent the wire from disconnecting, or they are remained because they cannot be removed during a manufacturing process to simplify the manufacturing process.
However, light from a backlight, which is a light source of an LCD, enters the semiconductor pattern to generate holes or electrons in the amorphous silicon layer, which causes light leakage current, and the light leakage current can be a cause for deterioration of the characteristic of an LCD. Especially, the light leakage current change the data signal, which results in change of pixel voltages transmitted to the pixel electrodes. Therefore, stripes having different brightness appear and move up and down when an image is displayed.